With my upcoming deck mods I will be glassing in a new section of deck. With that said I plan to clamp the new section in place and use several bandade type fiberglass stips to bond the two together. Then pull off the clamps after the glass is set up and then start glassing the whole length of sections from the bottom side of the repair/replacement area. Assuming I'll have anywhere from a 1/8 to 1/4 inch between the two sections I figured I would glass about a 3" wide fiber stip and repeat (overlay) with a 6" to 8" or so piece. Then move to the top side and repeat. Assuming this is OK what should I use in the gap area between the two sections so there isn't any void there before glassing the top side. Filler or resin? Or should I just pack in fiberglass with resin before moving to the top surface? Hope this makes sense.

Any input would be great here. If you see my other post here you can probably get a better idea of what I am up against.

Thanks,
John

PS I always thought it was best to leave a bit of a gap between the two sections your glassing together however please let me know your thoughts on this.

Thanks again

John I'll put up a graphic tomorrow to illustrate the method for butt joining fiberglass panels. For a structural deck joint you are on the tight track by clamping and tabbing (I call it stitching) Its the gap and outside that needs a perticular attention. Basically you want to tab the inside as you described above and leave the outside gap alone till the inside is completly tabbed and cured. Then scarf (grind) back the butt joint on the outside til you hit the tabbing on the inside then glass the joint together on the outside (if that made sense ) Assuming the deck is solid fiberglass with no core.

Dave very good point assuming there is no core and john are you actually going to be able to use clamps and if not might i suggest using butt blocks screwed in to place and tabbing inbetween them to give you the necessary bond to hold the deck in place .

Thanks once again Dave,
I look forward to seeing the illustration. I will be sure and post some pics as I move forward as well and you can stop me if you see something out of line or incorrect. I plan to reinforce the sections (panels) with some small like stringers from the underside as well before all said and done and then finish with new head liner (trunk material) so the reinforced area isn't so conspicuous. I need to update the headliner anyway to get rig of the 70's shag fuzz. LOL... The material in there now looks like it belongs in a 1978 Olds 98 covering the dash board. The only thing I am missing is the Dice. LOL...

Thanks again,
John

hey its probably easier to add the dice then replace the shag

heres a quick illustration. let me know if it makes sense. you want to avoid just filling the gap causing a hard spot. Its also my thought that tapering out the inside tabbing helps minimize a local hard spot as well.

Thanks Dave,
The illustration will help. I like the idea of tappering although my deck is a little thin but I will certainly do it to a degree anyway. Also after the glass work was is the best finishing products to work with. My thought was to rough it in with it in with duraglass and then a your normal feather light bondo. My goal would be to do a good glass job to minimize fillers however...

Thanks for your help.
John

i grinder finish everything to about 36 grit very close to the final shape (ya get good with it after twenty years ). Yes you are correct to use minimal fillers. Many times i will get the glasswork close enough that a couple coats of gelcoat will be all thats needed to finalize the surface. I would try and stay away from duraglass it really has no solid place in marine repairs. If you do use it, use it at a minimum. A good marine filler is 3M's premium marine filler, great stuff and works easy (best price at boatfix.com). You should always taper any repair in fiberglass all the way down to filling screw holes, its actually easier with thinner glass. Use a ratio of about 12:1 in other words if its an 1/8th inch thick grind it back about an inch and a quarter on each side. If you were to just fill the gap in the fiberglass without scarfing it back it causes a discontinuity in the surface that, through thermal cycling, will eventually show up as imperfections in the paint followed by cracks.

You can get the 3M Premium Marine Filler here too. They also carry the 3M high strength filler...